Conventionally, a car navigation apparatus having a function of displaying a list of the names of intersections either in the vicinity of a vehicle in which the car navigation apparatus is mounted or on a searched route while the vehicle is traveling along the searched route is known. Since this car navigation apparatus aims at informing the user of intersections in the vicinity of the vehicle or on the route so as to guide the user to the destination safely, it only has either the function of displaying the list of the intersections, or a function of displaying a map of an area including or intersection information about an intersection which is selected from the displayed intersection list (the intersection's name, the number of lanes of the intersection, etc.).
On the other hand, a car navigation apparatus usually has various surrounding facilities searching services, such as a vehicle position surrounding facilities searching service, a map point surrounding facilities searching service, a place-of-arrival surrounding facilities searching service, and a route surrounding facilities searching service. However, there have been provided no car navigation apparatus having a function of selecting a desired intersection from a list of intersections on a searched route to perform a search for surrounding facilities in the vicinity of the desired intersection.
Therefore, in order to search for surrounding facilities in the vicinity of a selected intersection, the user needs to cause the related art car navigation apparatus to stop route guidance and display a map of an area including the selected intersection on the screen, move a cursor to the desired intersection on the map using a remote controller or a joystick to set a point to be searched, and, after that, cause the related art car navigation apparatus to perform a search for surrounding facilities in the vicinity of the set point to be searched. This related art car navigation apparatus thus makes the user have the trouble of moving the cursor to the specific point on the map, and this operation of positioning the cursor at the desired intersection on the map causes the user to stare at the screen inevitably, thereby preventing the user from driving the vehicle. When the user can specify a point on the map by manipulating a touch panel with a finger, he or she does not need to stare at the screen. However, a drawback is that when the vehicle is currently located in a large city, for example, and a very large number of intersections are displayed on the screen, it is difficult for the user to specify the desired intersection correctly.
Although a method of allowing the user to directly specify an intersection on a map for route guidance can be alternatively considered as the method of specifying the intersection, when the map is automatically scrolled around as the vehicle moves, when the desired intersection exists in an edge of the screen display, when the desired intersection does not exist in the screen display because of the scale of the map, and when a large number of intersections exist in the screen display, it is difficult for the user to perform such an operation of specifying the desired intersection. Although a method of specifying an intersection by specifying a street which crosses the road along which the vehicle is currently traveling, and performing a search for surrounding facilities in the vicinity of the specified intersection can be also considered, it cannot be used when no name is given to the street and when the user does know the name of the street.
Patent reference 1 discloses, as a related technology, a route-to-be-traveled guidance apparatus for displaying both the current position on a map of a vehicle in which the guidance apparatus is mounted and the names of a plurality of intersections on a guidance route and in the vicinity of the current position on a display. This route-to-be-traveled guidance apparatus reads the names of a plurality of intersections on the guidance route and in the vicinity of the current position, which are selected through route searching, from a CD-ROM 7, and collectively displays the names of the plurality of intersections on a liquid crystal display on which a map, a mark indicating the vehicle, etc. are displayed. As a result, the user can grasp information about intersections located in a wide area surrounding the current position of the vehicle.
Patent reference 2 discloses a guidance route searching method which a navigation apparatus uses to search for a guidance route passing through roads which are to the user's liking and are extending to a destination. In accordance with this guidance route searching method, a first route from the place of departure to the destination is searched for, and intersections on the route are displayed in the form of a list. When the user selects a desired intersection from among the intersections on the first route, and specifies a traveling direction in which the vehicle should go out of the desired intersection, the method reduces the link cost of the road which is extending in the specified direction from the selected intersection, and searches for a route (i.e., a second route) extending from the intersection to the destination. The method then combines a part of the first route, which is extending from the place of departure to the desired intersection, and the second route into a guidance route.
Patent reference 3 discloses a navigation apparatus which can provide regulations, congestion information, etc. at an appropriate timing, and which enables the user to grasp the conditions of intersections in advance by displaying information about the intersections in advance, for example. This navigation apparatus includes a traffic information detecting means, such as a VICS receiver, for detecting traffic information which exists on a road along which the vehicle should travel, and an intersection information providing means for, when the traffic information detecting means detects traffic information which exists on a road, providing detailed information about the names of intersections located on this side of a location associated with the traffic information which exists on the road along which the vehicle should travel, the distance to each of the intersections, marks respectively indicating the intersections, an intersection map, a lane map, a road map, etc.
[Patent reference 1] JP, 9-133541,A
[Patent reference 2] JP, 2003-121186,A
[Patent reference 3] JP, 2002-286476,A
Related art car navigation apparatus have some surrounding facilities searching services, such as a vehicle position surrounding facilities searching service, a map point surrounding facilities searching service, a place-of-arrival surrounding facilities searching service, and a route surrounding facilities searching service, as mentioned above. However, since each of these facilities searching services has an advantage and a disadvantage, they are used so as to be complementary to one another. For example, when the user desires to search for a gas station in a hurry, the related art car navigation apparatus can perform a vehicle position surrounding facilities search. However, there is a possibility that gas stations which exist in a direction opposite to the traveling direction of the vehicle are also searched for in this vehicle position surrounding facilities search. In such a case, since only gas stations which exist in the traveling direction can be searched for when a route surrounding facilities search is performed, the disadvantage of the vehicle position surrounding facilities search can be removed.
However, since all locations on the route become a target to be searched in the route surrounding facilities search, unnecessary gas stations in the vicinity of the point of arrival are searched for, and therefore the route surrounding facilities search takes relatively long time. Therefore, it is necessary to take measures, such as a measure of restricting the area to be searched or the number of facilities to be searched. Under such conditions, the related art car navigation apparatus needs to further have a function of complementing the route surrounding facilities searching function. That is, the related art car navigation apparatus needs to have a facilities searching function of restricting the target to be searched to facilities which exist in the traveling direction of the vehicle and in the vicinity of the vehicle, making the area to be searched substantially wide, and being able to search for the facilities in a short time.
In addition, since there is a high possibility that the user performs mistaken operations under conditions that the use needs to cause the related art car navigation apparatus to perform a search for facilities in a hurry, the number of times that the user performs operations to cause the related art car navigation apparatus to perform a search for facilities has to be reduced as much as possible to simplify the procedure, and the length of time that the user stares at an operation screen display for the procedure has to be reduced. Furthermore, a function of properly searching for information which the user desires to have and providing it for the user so that the user does not need to redo the operations for searching is needed.
The present invention is made in order to meet the above-mentioned requests, and it is therefore an object of the present invention to provide a car navigation apparatus which can provide information about facilities in the vicinity of an intersection quickly according to a user's simple operations.